[The following paragraph was effective for audits of financial statements for periods beginning on or after January 1, 1989. It was amended, effective for audits of fiscal years beginning on or after December 15, 2010. See PCAOB Release No. 2010-004.

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The auditor should evaluate significant unexpected differences. Reconsidering the methods and factors used in developing the expectation and inquiry of management may assist the auditor in this regard. Management responses, however, should ordinarily be corroborated with other evidential matter. In those cases when an explanation for the difference cannot be obtained, the auditor should obtain sufficient evidence about the assertion by performing other audit procedures to satisfy himself as to whether the difference is a likely misstatement. fn 3 In designing such other procedures, the auditor should consider that unexplained differences may indicate an increased risk of material misstatement. (See section 316, Consideration of Fraud in a Financial Statement Audit.)